Because you WILL GET A WRONG CODE. There is nothing we can do to help you in case you add this way since our provider will not refund or check these codes. The problem with theses phones is that the operator will change the codes from the defaults and the factory default codes will be wrong. The only way to get the unlock code for these models is to add them by operator, as long as the operator is supported by Thank you for understanding.

Don't request code for AT&T and T-Mobile USA as 100% of code are Not Found for these two Networks.
If you WILL GET A WRONG CODE. There is nothing we can do to help you in case because codes comes directly from DATABASE. and its never b wrong .maybe you have counter blocked or operaor maybe change this code to another !
No Refundable
If your IMEI will be re-locked, then it will not be refunded.